The U.S. Army Criminal Investigation Command (CID) at Fort Bragg and the Fayetteville Police Department are behind the now $25,000 reward for information.
Pfc. Kelli Bordeaux was last seen leaving a Fayetteville bar called Froggy Bottoms with an acquaintance in the early morning hours of April 14, 2012.
Fayetteville police and an army of volunteers spent months scouring woods and fields in the Ramsey Street area, but they have found no trace of the 24-year-old.
"It's really unbelievable. That you wake up every day and still don't know where she is, " Bordeaux's sister, Olivia Cox told ABC11 earlier this month.
Bordeaux, who is a combat medic, is described as having a small build -- standing at 5 feet 1 inch tall and weighing about 105 pounds. She has blond hair and brown eyes.
Authorities are asking anyone who has information about Bordeaux's whereabouts to contact Special Agent Martin Smith with CID at (910) 396-8777 or the military police desk at (910) 396-0392.
Bordeaux's family also keeps a Facebook page called "Find Kelli Bordeaux" updated with information. While police are not commenting on a suspect, the family keeps a picture of Nicholas Holbert on the page.
Holbert is a convicted sex offender and told authorities he gave Bordeaux a ride home from the bar the night she disappeared. He remains in jail on unrelated charges.